Alterations of resting-state functional network connectivity in patients with noise-induced hearing loss: a study based on independent component analysis

Objective: To evaluate resting-state functional network connectivity (FNC) alterations in patients with occupational noise-induced hearing loss (NIHL) using an independent component analysis (ICA). Method: 79 mild NIHL patients (MP), 32 relatively severe NIHL patients (RSP), and 84 age- and education-matched healthy controls (HC) were recruited. All subjects were tested using the Mini-mental State Examination scale test (MMSE) and scanned by T1WI3DFSPGR, resting-state functional magnetic resonance imaging (RS-fMRI) sequence and analyzed by the ICA. All patients were tested using the tinnitus handicap inventory scale (THI) and the Hamilton Anxiety scale test (HAMA). Result: Using the ICA, 7 resting-state networks (RSNs) were identified, and FNCs were compared among the three groups. Compared with the HC, the MP showed increased FNC within the executive control network (ECN) and enhanced FNC within the default mode network (DMN) and the visual network (VN). Compared with the HC, the RSP showed decreased FNC within the ECN and auditory network (AUN), DMN and VN. No significant changes in FNC were found in the MP compared with the RSP. Furthermore, the correlation analysis between the noise exposure time and hearing loss level and the exposure time and HAMA scores were both negative, and there were no significant correlation between the FNC correlation coefficient of the abnormal RSNs and the hearing level, noise exposure time, and HAMA. Conclusion: These findings indicate that different degrees of NIHL involve different alterations in RSNs connectivity, and may reveal the neural mechanisms related to emotion-related features and functional abnormalities following long-term NIHL.